before
  case x of { 1->1; _ -> case C of { A -> 2 }}
transformed to
  case x of { 1->1; _ -> neverMatchingCase }
now it transforms to
  case x of { 1->1;}

completing Sjaak's changes in module trans caused by exchanging the transform and convertcases phases

 - dictionary arguments added properly
 - coercion of function types